using System.Net;

namespace SddpViewer;

public class IpRangeHelper
{
  public static IEnumerable<IPAddress> GetIPRange(IPAddress startIp, IPAddress endIp)
  {
    uint start = IpToUint(startIp);
    uint end = IpToUint(endIp);

    if (start > end)
    {
      (start, end) = (end, start);
    }

    for (uint current = start; current <= end; current++)
    {
      yield return UintToIp(current);
    }
  }

  private static uint IpToUint(IPAddress ip)
  {
    byte[] bytes = ip.GetAddressBytes();
    if (bytes.Length != 4)
      throw new ArgumentException("Nur IPv4 wird unterstützt.");
    return (uint)((bytes[0] << 24) | (bytes[1] << 16) | (bytes[2] << 8) | bytes[3]);
  }

  private static IPAddress UintToIp(uint ip)
  {
    byte[] bytes = new byte[4];
    bytes[0] = (byte)((ip >> 24) & 0xFF);
    bytes[1] = (byte)((ip >> 16) & 0xFF);
    bytes[2] = (byte)((ip >> 8) & 0xFF);
    bytes[3] = (byte)(ip & 0xFF);
    return new IPAddress(bytes);
  }
}